3 Chess Prodigies Show Their Stuff

By HAROLD C. SCHONBERG

Published: September 18, 1987

Jessica and John played chess, and Susan, serious Susan, watched without any expression on her face. John chattered away during the fast game. Jessica kidded around also. The game was a draw, and there was a brief analysis. ''Suppose,'' Jessica said, ''I pushed pawn to b6?'' Said John: ''Wouldn't work, because . . .'' and he showed why. That is the way world chess champions talk.

It so happens that John and Susan are world chess champions even though they are so small thay could hide under a cabbage leaf; and Jessica missed out by a hair. They and a third young world champion -Yvonne Krawiec - are being entertained in New York this weekend. Nine-year-old John Viloria from Yonkers is the under-10 boy champion of the world. Susan Urminska from Kapa, Hawaii, even younger at 8, is the under-10 girl champion. Yvonne Krawiec, 11, from Hacienda Heights, Calif., won the under-12 girl championship. She was due to be in New York yesterday.

Jessica Ambats from New York, who is now 14, had a heartbreaking experience. She tied for first place in the under-14 category only to lose on a tie-break. In a tie-break, the officials of a tournament study the games of the tied players and give the honor to the one who faced the stronger competition. Jessica will join her younger colleagues this weekend. A Simultaneous Exhibition

It is the first time that three young American chess players have so simultaneously distinguished themselves. They won their titles last July in Puerto Rico, coming out ahead of some of the best young players the world has to offer. To celebrate their victory, the American Chess Foundation has brought them to this city. They will be photographed today atop the World Trade Center. The four of them will give a free simultaneous exhibition at the Manhattan Chess Club tomorrow at 2:30 P.M. (visitors are welcome), playing young people of their own ages. For three days they will be wined and dined. Well, maybe not wined. Jessica, John and Susan were interviewed at the Manhattan Chess Club, where at least John and Jessica felt perfectly at home. Susan looked a little awed, though that did not stop her from playing a game with an elderly woman who is a member of the club. The three youngsters had fun analyzing games, meeting other chess players and playing fast chess with each other. John and Jessica acted somewhat as guides. They live in the vicinity and are no strangers to the Manhattan Chess Club. But as Susan said, and as Yvonne said in a telephone interview, big chess clubs and strong competition are not found in Hacienda Heights or Kapa.

Like most rated chess players, these children learned the game at home, from their parents or siblings. They all started around 5 or 6. ''I was real little,'' said Yvonne. ''I found out that I liked to win.'' Yvonne has her eyes set on the women's world championship. Already she knows her own style. She says that she is an attacking player, but that she has problems in the openings.

''If they go off book,'' she said, ''I don't know what to do next.'' Going off book means making a departure from closely analyzed, published lines. Chess players, brutes that they are, do this to confound their opponents. Yvonne spends about an hour a day working on chess, and every Friday she has a session with her teacher, Jeremy Silman, whose services are paid for by the American Chess Foundation. The Same Pattern

Each of the others follows much the same pattern. John worked with Lev Alburt, a grandmaster who is a former United States chess champion, and is now in the hands of Vitaly Salzman, an international master. (Mr. Alburt has said that John is the most promising young player in America today.) When John went to Puerto Rico, he was certain, he says, that he would win ''once I heared that the Russians weren't there. Wait! That's only a joke.'' Did he really think he would win? ''Yep.'' Maybe he knows how good he is. He ran away with his competition, winning nine out of 10 games and drawing the 10th.

The American Chess Foundation is seeing to it that Susan, who never has had a teacher, will get one this fall. She picked up the essentials of chess from watching her older brother, Oleg, play with friends. Susan is a quiet girl but is vehement about one thing. She is going to be a chess player for the rest of her life.

Already John and Jessica are, in a way, professionals who talk like professionals. They do not make a living playing chess, but they are already playing in tournaments, striving to get their ratings up, anxious to meet strong players. Jessica's rating is 1901. John's is 2017. Those numbers may not mean much to the uninitiated, and they are a good distance from the lofty grandmaster level of 2,500-plus. But what the numbers do mean is that you do not want to play either of these young people for any sizable amounts of money.

The Manhattan Chess Club is on the 10th floor of the Carnegie Hall Studios at 154 West 57th Street. Information: 333-5888.